The utilization of cellulosic waste materials, such as cornstalks, sawdusts, straws, bagasse, and the like, hereinafter referred to as cellulosic material or cellulosic residue, has been the subject of strong interest recently, particularly with respect to utilization of such waste materials for developing alternate sources of fuels, feedstuffs, chemicals and other useful products.
It is known that cellulosic materials include three principal components--cellulose, hemicellulose and lignin. Methods for extraction or hemicellulose heretofore have been suggested and/or utilized and such extracted hemicellulose can be utilized by many existing methods including hydrolysis, fermentation, pyrolysis, and the like.
Lignin has also been isolated from cellulosic materials and since it is higher in hydrogen and carbon and lower in oxygen content than cellulose and hemicellulose it has the highest fuel utility of the three. Isolated lignin can be burned to generate steam and electricity and also can be used to produce a number of useful products including vanillin, dimethylsulfoxide, dimethyl sulfide, and methyl mercaptan and catechol.
Recovery of cellulose and/or utilization of the same, as by hydrolysis to provide glucose, has presented a problem heretofore primarily due to the crystalline structure of the cellulose molecules and the presence therein of a lignin seal.
While attempts have been made to hydrolyze cellulosic materials by means of acids or enzymes, such attempts have not been completely successful, at least not in providing an economically attractive method that is capable of providing a satisfactorily high yield of glucose from the cellulose in such cellulosic materials.
Also, while solvents have been suggested and/or utilized in conjunction with cellulosic materials, improvements in such solvents can still be utilized in recovering cellulose. In this regard, dissolution of pure cellulose using a ferric sodium tartrate based solvent heretofore has been suggested. See, for example, Valtassari, Papper och Tra 4 (1957) 243.